This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
It has been more than five years since the first edition of this book presented readers with a new perspective regarding the modification of plastic surfaces. The popular reception of the book and the rapid expansion in the analysis of materials modified by atmospheric pressure-based surface modification techniques has called for a new edition to assist these new efforts.
This edition (1) provides technical updates and clarifications in Chapter 7 of the original book, (2) adds summaries of new developments in the surface modifica-tion of additional base materials along with annotated bibliographical references at the end of Chapter 7, and (3) elucidates subtle issues that readers have found in need of elaboration.
Practitioners within the plastics and packaging industries who have sought in-sights from this book before should find the revised edition more comprehensive in scope, while those who have waited for scouts to carve the path will find this road towards improved surface modification paved and tested.
My main audiences remain manufacturers, converters, and processors of materials who are seeking to benefit from surface modifications and chemical functionaliza-tions at the atomic and molecular levels. I hope that each of these groups will find the additional content presented in this book to be both inspirational and instru-mental in tackling new challenges in their respective market spaces.
Preface to the Second Edition
Polymer surface modification is a topic that has been the object of a large number of investigations by academia and industry, but relatively little attention has been paid to surface activation technologies which, when appropriately utilized, make specific polymer-based surfaces receptive to value-adding interfaces such as inks, coating and adhesive formulations. Adhesion strength is generally determined by the properties of a base material and its interface. Optimizing adhesion strength can be accomplished by modifying these interfaces chemically and physically. As polymers are continually engineered to meet new product application require-ments, optimizing the activation of these surfaces requires a fresh look at cost effective ways to etch, clean and functionalize them. These demands require detailed information on the surface treatment of classic materials, as well as an examination of the latest surface treatment machine designs available anywhere in the world today which are used to process these materials. There are four full chap-ters devoted specifically to corona, ozone, flame, and plasma discharge surface treatment technologies; and an interesting and useful identification of common adhesion maladies.
The aim of this book is to describe the primary polymer adhesion issues faced by manufacturers, processors and converters, to outline a variety of methods for attain ing an appropriately activated surface, and to provide the diagnostics for va-rious adhesion promotion issues which the reader seeks to trouble-shoot.
Preface to the First Edition
As a complete reference source for surface modification of polymers, this book re-views traditional and conventional methods for improving the adhesion of inks, coating adhesives, metals, and other adherends to polymers and introduces new methods for molecular engineering polymer surfaces to enhance their adhesion to a wide range of materials. In addition, this work serves to turn the vast amount of disparate information regarding plastics surface modification from wide ranging sources into practical application knowledge. In order to make this information most useful for practitioners, consultative data is arranged in consistent formats.
Modification of surface properties is based on the principle of the formation of physical, chemical and multi-layer surface structures of various complexities, including the deposition of amorphous films, which are finely dispersed by both atmospheric and vacuum processes. Plastic surface modifications with these types of discharge technologies are well known methods which can dramatically improve functional performance. Targeted variations of surface characteristics of non-con-ductive materials include wettability, adhesion, water and chemical resistance, oxygen, and water vapor transmission, or a controlled response to changes in environmental factors such as pH, all while retaining the bulk properties of the original polymer substrate. Desired variations of surface characteristics of con-ductive materials include corrosion resistance, strength, wear resistance, fatigue strength, electric-erosion resistance, and many others.
In recent years, inorganic substrates have been utilized as chemically and ther-mally stable substrate materials for graft polymerization modification processes. Covalent bonding of polymeric surfaces onto inorganic substrates has been used to change surface chemistry, surface structure, and native topology. Atomic force microscopy (AFM) has become a popular method of investigating the surface microstructure of polymers. AFM characterizations paired with analysis from scanning electron microscopy (SEM) are now routinely used to elucidate changes in surface topography and structure which result from atmospheric and vacuum discharge treatment to polymer surfaces, including graft polymerization modifica-tion of inorganic materials. In addition, electron spectroscopy for chemical analy-
Introduction1
2 1 Introduction
ses (ESCA) is routinely used to generate spectra which can also provide informa-tion about a surface’s chemical environment or oxidation state.
It is through the application of these surface modification methods and surface analytical techniques that decorating and layering (laminating) processes can ultimately optimize adhesion promotion at the most cost-effective scale of end-use processing. Achieving adequate adhesion to polymers is a recurring and difficult problem throughout many industries, and most notably within the printing and packaging industries. Historically, various surface treatments have been used to improve the adhesion of coatings to plastics, including corona, flame and other forms of surface preparation. High energy density treatments such as cold gas plasma methods are gaining greater acceptance for substrate surface modification because they deliver reactive species (photons, electrons, free radicals, and ions) that interact with the polymer surface and change its chemistry and/or mor-phology at atmospheric pressure. Because these processes can be readily incor-porated into printing and packaging manufacturing operations, this work will be useful in defining the necessary modifications to these material surfaces so that individual or multilaminate composite structures can meet or exceed end use re-quirements.
When addressing the adhesion of polymers to interfacing materials, the primary and foremost challenge is to understand the fundamental driving forces which can initiate the development of adhesion strength between polymer-to-polymer, poly-mer-to-metal, polymer-to-ceramic, or polymer-to-inks coatings and adhesives. These interfaces also exist in multivariate environments, such as heat and humid-ity, which also must be examined. Ultimately, it is the polymer and the interface chemistry that determine adhesion. However, there can be adhesion failure be-tween the polymer and an inorganic, such as a metal, due to an oxide layer that is weakly attached.
That being said, this work will focus fundamentally on the bonding issues associ-ated with polymers because of their unique deformation character, low modulus, and long chain structure.
Many polymeric materials inherently have a low surface energy that results in poor surface adhesion or even complete adhesion failure. This makes it difficult for inks, paints, adhesives and other coatings to properly wet-out and adhere to the surface of these substrates. Proper surface preparation of these materials will in-crease surface energy, improve surface adhesion properties, and add value to the product and the process. However, one must keep in mind that it is the bulk me-chanical properties of the polymer that control the interfacial forces, which in turn influence adhesion. We will be subsequently reviewing various substrate orien-tations, from oriented and metallized films to spunbonded polyolefins and molded polymers, in order to examine their bulk structures for their ability to endure mechanically-induced deformations to allow for surface roughening and chemical covalent bonds to achieve requisite adhesions.
It is well known that polymer chain entanglement is the primary source of a poly-mer’s strength. It is also known that over time polymeric materials can become increasingly semi-crystalline, making their surfaces even more difficult to accept surface modification techniques. The process of axially or biaxially orienting poly-mer films, for example, strengthens these materials as their chains become stretched. It is therefore common practice for surface modification techniques,
Primary Polymer Adhesion Issues with Inks, Coatings, and Adhesives
2
4 2 Primary Polymer Adhesion Issues with Inks, Coatings, and Adhesives
such as corona discharge, to take place immediately following the orientation phase.
�� 2.1� Cast and Blown Films
The cast film process involves the extrusion of various polymers which are melted through a slot or flat die to form a thin, molten sheet or film. This melted film or “extrudate” is typically laid to the surface of a water-cooled and chrome-plated roll by a blast of air from an air knife or vacuum box. Cast film extrusion orients mole-cules in the machine direction only, producing a large difference in machine and transverse directional properties. This means that the chain molecules become aligned in the cast direction. This will increase the tensile performance in that direction, and forms what is known as “uniaxially” oriented film, whereby the gauge of the film will be in relatively straight lanes. However, there are other cast film extrusion disturbances, notably the effect on optical properties, which can be attributed to the structure of the polymer bulk, the structure of the film surface, crystallination roughness at the surface, and surface roughness by the extrusion process. Molecular weight, molecular weight distribution, chain branching, shear strain, melt flow rate, relaxation time, elasticity, orientation, processing conditions, and cooling rate must also be considered. They contribute not only to the formation of surface roughness but also their affect on surface adhesion. For example, a narrower range in molecular weight distribution leads to a more uniform crystal size distribution and thus to lower surface roughness and better optical properties. It can also be expected that surface modification techniques applied directly after extrusion will encounter less surface crystallination, which will enable greater surface roughening and a functionalization effect on a relatively chemically inert surface to promote future interfacial adhesion.
Cast film extrusion is used in manufacturing polypropylene films and requires greater surface pretreatment power density (possibly 2–3 times) compared to other polyolefin films. With blown film extrusion processes, polyethylene films are typically used and require pretreatment on both sides. Considerable amounts of slip additives, used to lubricate the surface of these films for processing ease, can be prevalent within the resin and migrate to the surface of the film within a few days after extrusion. Although there is potential for the additive to mask-over treat-ment, it is far more important to surface treat immediately after extrusion, since it will be practically impossible to do so after additive migration to improve surface properties sufficiently for ink, coating, or lamination adhesion.
It is interesting to note here that with respect to heat-sealing behavior, some re-search indicates that a primary effect of surface pretreatments such as corona on
52.2 Metallized Films
blown linear low density polyethylene films, for example, can be a change in the failure mode of heat seals from a normal tearing or inseparable bond to a peelable seal. More specifically, corona discharge has been determined to increase the seal initiation temperature by 5–17 °C and decrease the plateau seal strength by 5–20 % as the treat level, or wetting tension, increases from 31 to 56 dynes/cm. These co-rona treatment effects have been attributed to cross-linking during the process, which restricts polymer mobility near the surface and limits the extent of inter-diffusion and entanglements across the seal interface. Results of heat-sealing studies with electron-beam-irradiated polyethylene, chemically oxidized poly-ethylene, and corona-treated polypropylene provide indirect evidence for the pro-posed surface cross-linking mechanism [1]. However, it is quite possible that this observation can also be attributed to an “over treatment” effect from discharge power densities which are higher than required. Because of the recurrent need for surface preparation optimization at extrusion, the importance of corona and other surface treatment discharge technologies requires closer process control examina-tions and will be discussed in depth to describe these surface mechanisms.
�� 2.2� Metallized Films
In the metallization process, a layer of metal is deposited on plastic films using several different methods, ranging from vapor deposition to electroplating. When preparing surfaces for adhesion, one must consider the surface differences be-tween the type of film substrates, the potential variations of film characteristics within different substrate families, variations with use of the same substrate be-tween vacuum metallizing chambers, and any possible variations within an end-use application, even when using identical films.
It has been practical experience over many years that polyester films and oriented polypropylene have sufficient metal adhesion to be the most widely used in flexible packaging applications. As stated previously, there can be significant differences among these metallizing substrates. An initial consideration is their respective surface polarities, either inherent or pre-conditioned. In the case of the latter, a non-polar surface can be prepared to chemically and molecularly bond to the deposited aluminum layer by oxidizing the surface. This is typically accomplished by contributing oxidation, peroxides, alcohol, ester, ether, or aldehyde functional groups, which will bond well to aluminum depositions. As inferred with extruded films earlier, an overtreatment of an organic surface can actually cause metal adhe-sion to become quite poor. This introduces the concept that overtreatment can over-develop low molecular weight organic materials at the surface layer, causing the deposited metal to lose contact with the base polymer. This creation of what is
6 2 Primary Polymer Adhesion Issues with Inks, Coatings, and Adhesives
known as a “weak boundary layer” weakens the mechanical surface bond between the metallized surface and the base film, potentially causing a failure of the metal to adhere. This metal bonding failure can also result from the surface migration of film processing additives, which are used to reduce the film’s coefficient of friction for ease of processing.
As was noted earlier, a polymer surface may not necessarily need to be functional-ized in order to create a strong surface bond with a metal. However, it is necessary for the surface of such polymers to be crosslinked. Schonhorn [2], for example, showed that the integrity of crosslinked surfaces will be highly dependent on the level of high-energy processing, such as the metallization process itself, or a form of surface treatment. The type of polymer used for the metallization process may be more adversely impacted at its surface by a pretreatment approach such as corona, flame, or plasma, although Schonhorn demonstrated that surface degra-dation effects can vary. To mitigate such an impact, more controllable surface treat-ment approaches, such as vacuum or atmospheric plasma, can avoid the formation of weak boundary layers by “pre-cleaning” the surface of low molecular weight organic materials and by introducing functional groups that are appropriate for the specific polymer film to be metallized (see Figure 2.1).
Figure 2.1� Corona treatment of metallized webs
These processes must, however, also be controlled, most notably relative to the type of functional groups introduced and the temperature of the film during metal-lization to optimize the metal-to-polymer bond.
Another important point regarding successful metallization of polymer films is that the deposition of aluminum on, e. g., flexible packaging films, is generally only one aluminum crystal thick. This layer of crystals is porous due primarily to the formation process of the metallization layer and by residual surface contamination during the metallization process [3]. The presence of this inherent porosity empha-sizes the importance of managing the surface treatment process to an optimal state so that the performance of metallized films in metering light, oxygen, and moisture transmission for flexible packaging can in turn be optimized.
72.3 Foams
�� 2.3� Foams
Polyurethane (PUR) foams, both flexible and rigid, account for the largest segment of foams marketed worldwide. Polystyrene foams, both extruded and expanded beads (EPS), are the second largest family of foamed plastics, followed by polyvinyl chloride (PVC) foams. Polyethylene and polypropylene foams also have a preva-lence, and particularly cross-linked polyethylene foams. All foams, however, are manufactured by a common extrusion process, consisting of the mixing of a chem-ical foaming agent with the specific polymer to be extruded. The heat generated during the extrusion process to melt the polymer also decomposes the chemical foaming agent, resulting in gas being released. This gas is dispersed in the poly-mer melt and expands upon exiting the die. Dense foams have what is considered a “closed-cell” structure, meaning that the gas bubbles that form and disperse dur-ing the extrusion process remain permanently locked into the cured foam. Because there are no interconnections between individual bubbles, the foam absorbs little in the form of liquids and also resists the passage of liquid vapor. Low-density foams are considered “open-cell” foams and have a structure with a series of small interconnected passageways. These open cells can be permeable to liquid vapors.
Polymeric foams can be difficult to surface treat for adherence to other materials. Manufactured using a variety of thermoplastic and thermoset resins, these foams can have either a high resident surface energy (such as for styrenes, PU, epoxy) or low surface energy (such as for polyethylene, polypropylene, EPDM).
When open-cell foams manufactured from low surface tension polyolefins require surface treatment, the filamentary discharges from a corona treater will typically find a path to ground through the open passageways and create a high incidence of pin-holing of the foam surface structure. Pin-holing is particularly acute as the foam thickness increases beyond the optimum corona discharge gap, usually ap-proximately 1.5 mm between the foam surface and the electrode. This is because the increased gap increases the “gap voltage” requirement, causing a high voltage arc to bridge the gap and typically through open and closed cell foams alike. Considering continuous atmospheric treatment technologies, pin-hole effects can be mitigated by using either flame plasma or atmospheric chemical plasma surface treatments, which ionize gases and require lower breakdown voltages compared to that of air.
Once the surface tension of foams is sufficiently raised, adhesives can more effec-tively wet and bond to open- and closed-cell foams. In open cell foams, adhesives can spread into the pores of the foam. Although the benefit can be superior adhesion as a result of mechanical bonding, the functional properties of the foam can be adversely affected. Typically, permeability and thermal properties of the foam may be compromised to the point where the structural integrity of the foam is weakened. This is particularly true when introducing solvent-borne adhesives,
8 2 Primary Polymer Adhesion Issues with Inks, Coatings, and Adhesives
for example, which can swell the foam structure. To compensate for these potential effects, the adhesive is recommended to be applied to the interfacing substrate, which is typically less porous and will minimize the spreading of adhesive into the foam’s passageways. These issues are not as problematic when using adhesives that will not adversely react with polymeric foams, such as water-borne adhesives and high solids epoxies and polyurethanes.
When applying adhesives to closed-cell foams, the adhesive cannot seep or pene-trate into the foam structure. As such, it is more critical that pre-treatment be em-ployed to establish a micro-rough and functionalized surface to allow the adhesive to mechanically and chemically bond to the surface.
�� 2.4� Textiles, Filaments and Yarns, and Nonwovens
Most manufactured fibers for textiles are made from wood pulp, cotton linters, or petrochemicals. Those fibers manufactured from petrochemicals include nylon, polyester, acrylic, and olefin. Most textiles are produced by twisting fibers into yarns and then knitting or weaving the yarns into a fabric.
Textile production traditionally involves a number of wet processes that may use solvents. Emissions of volatile organic compounds (VOCs) mainly arise from textile finishing, drying processes, and solvent use. VOC concentrations vary from 10 mil-ligrams of carbon per cubic meter (mg/m3) for the thermosol process to 350 mg carbon/m3 for the drying and condensation process.
Process wastewater is a major source of pollutants. It is typically alkaline and also contains solids, oil, and organics [4]. The process of promoting pigment and dye uptake on textile materials can also involve aqueous emulsion-type agents to meet requirements for use, such as fade resistance, permanence under repeated laun-dering, and abrasion resistance. As such, textile manufacturers and end-users alike have been searching for ways to improve the surface properties of natural and man-made fibers, while minimizing the impact on the environment. Speci-fically, there is a need to improve adhesion, wettability, printability, and dyeability without the need for additional wet processes. Examining nonwovens made from low polarity, low surface tension and highly crystalline polyolefins will exemplify one of the most challenging textile materials, which typically requires pretreat-ment to promote adhesion. Methods of modifying fiber properties to make poly-propylene dyeable, including the process of copolymerization with polymers that can be dyed, are common. Traditional latex systems and primers with low melting points have been used to coat fabrics to promote ink adhesion, heat-sealing, and thermoforming performance.
� Flow meters for air and gas, to ensure precise reproduction of process para-meters.
� Flame power control, to control BTU output and thermal efficiency. � Methane, propane, or butane compatibility, for grafting various carbon-based functional groups.
� Integrated ignition and flame detection electrode for ignition safety.
To re-establish the groundwork to better understand this topic, the delivery of current into a neutral gas causes a portion of the gas particles to be converted by ionization into charged particles. This ionization creates a plasma which is gener-ated by electromagnetic fields and denoted as an electrical discharge. This elec-trical/gas discharge plasma is correctly characterized as a partially ionized gas with neutral particles, along with a counterbalancing amount of negative electrons and positive ions. There can also be plasmas where all particles are ionized, and plasmas with negative ions. These types of plasmas will not be discussed here.
There are a wide variety of plasmas which can be generated under a number of varying conditions. One of these key conditions is the pressure of the working plasma gas. At specific temperatures, the pressure of the gas will predetermine the density of these gas particles, and ultimately the frequency of collisions between particles. Under this assumption, the higher the gas pressure, the higher the fre-quency of particle collisions. The higher the collisional frequency, the higher the probability that a steady state will eventually be achieved whereby the collisional energy will establish itself at equilibrium. In this equilibrium state, all ionized particles (and the gas) will have the same temperature.
Particle collisions can be subdivided into two categories: elastic collisions and inelastic collisions. Elastic collisions will not change the internal energy of neutral species, but will slightly raise their kinetic energy. With inelastic collisions, the electrical structure of the neutral species will be modified whereby excited species or ions will be created. The lifetime of these species will be very short. Species known as metastables will also achieve an excited state, but also exist with long lifetimes since their decay by radiative emissions is precluded since no energy can be transferred without collisions.
For many roll-to-roll plasma applications which require aggressive plasma–sub-strate surface interaction without surface degradation, temperature limitations are
90 7 Chemical Plasma Treatment Technologies: Features and Application Benefits
key to successful surface modification. For example, these temperatures can exceed 900 °C but for other applications temperature limits must be near room tempera-ture. When the latter is the case, a cold plasma is required which does not exist in a thermal equilibrium. It is understood that non-equilibrium plasmas will not have significant particle collisions since the operational pressure will be low. Further-more, low pressure plasma systems require very capital intensive (and large) vac-uum chambers and pump systems for roll-to-roll materials. As such, there has been significant progress in recent years in development of cold atmospheric plasmas which operate at non-equilibrium as an alternative for low pressure regimes.
This section summarizes the principles and characteristics of cold atmospheric plasmas for roll-to-roll applications and their differences from low pressure plas-mas in order to provide a better understanding of the capabilities and limits of non-equilibrium atmospheric plasmas for roll-to-roll materials. A review of cold atmospheric plasma sources, their capabilities, surface effects relative to achieved results, and a discussion of roll-to-roll application benefits will follow.
Polymer Film Application ProfilesIn an attempt to profile those materials which can be processed by atmospheric plasma systems, a brief discussion of dielectrics must take place. Firstly, the most representative non-equilibrium (partial discharge) plasmas are dielectric barrier discharges and coronas. The dielectric barrier discharge was first invented in 1857 by Siemens, and originally designed for ozone generation. After extensive research in subsequent years, it was determined that parallel insulated electrodes with a predetermined gap created a discharge in a number of individual (but location- repetitive) filamentary micro-discharge channels. It was ultimately demonstrated that the plasma parameters of these channels are controllable, and therefore the dielectric barrier discharge could be optimized for applications such as roll-to-roll orientations.
Secondly, atmospheric plasma barrier discharge systems for roll-to-roll, poly-mer-based applications can have a wide variety of electrode/ground roll configura-tions, and are typically characterized by the presence of one or more dielectric layers, such as ceramic or glass, located on the electrode and ground roll surface. The gap between the electrode and ground roll (including the applied dielectrics) for atmospheric pressure plasma systems for these applications will range from 1 to 5 mm. Multiple arrangements of these electrode systems are quite common, and the use of large arrays of electrode bars contained within assemblies is prevalent.
Also adding to the dielectric equation of atmospheric plasmas for roll materials is the type of gas media used to create the discharge between the electrode/ground roll systems. The mean free path and molecular weights of gas media will alter the existing dielectric properties resident with the electrode and ground roll. The gas
media determines in part the characteristics of the individual micro-filamentary discharges which are spread at the dielectric surfaces. The dielectric barrier designed into roll-to-roll systems ultimately controls the amount of energy and charge comprising the micro-discharges, and the uniform distribution of the micro-discharges over the electrode face.
Finally, the roll-to-roll material itself presents dielectric variations inside the reac-tion gap. Most polymer films, for example, are dielectrics (insulators) which will resist the flow of an electrical current. However, despite this property, a dielectric breakdown can occur at a sufficiently high voltage in order to allow for current transmission and surface modifications. During the voltage increase period, micro-discharges will be generated which will impact the dielectric surface. These discharges will occur at unique locations since the electrical field will be reduced by the presence of remaining or residual charges which reside at the locations where the micro-discharges had already occurred. When voltage is in the reverse period, fresh micro-discharges form at the previous micro-discharge location. As such, the low voltage–high frequency profile of most atmospheric plasmas will generate micro-discharges at these original locations. However, not all polymers will behave the same way when they are subjected to voltage. As such, they are classified as being either polar or nonpolar to describe their variations in dielectric behavior. Polar polymer films do not have full covalent bonding within their molec-ular structures as there is an imbalance in the electrical charge of the molecule. Specifically, dipoles are created by an imbalance in the distribution of electrons and in the presence of an electric field the dipoles will attempt to move to align with the field. This creates “dipole polarization” of the material and because move-ment of the dipoles is involved, there is a time element to the movement. Some examples of polar roll polymer films include PVC and polyamide. Polymer films which are nonpolar have symmetrical molecules, do not have dipoles, and are fully covalent. The application of an electrical current will not align dipoles. Examples of nonpolar polymer films are fluoropolymers, polyethylene, polypropylene, and poly-styrene. These polymers also tend to have high electrical resistivity and low di-electric constants. Surface resistivity is the measure of material resistance to a surface flow of current and is defined as the ratio of applied direct voltage and the current along the surface of the material, per unit width. The dielectric constant measures how well a material separates the plates (electrodes) in a capacitor and is defined as the ratio of the capacitance of electrodes with the dielectric material between them to the capacitance of the same electrodes with a vacuum between them.
92 7 Chemical Plasma Treatment Technologies: Features and Application Benefits
Digital Inkjet Inks
Organic Solvent - Based InksSurf
ace
Ener
gy (m
N/m
)
Substrates
10
20
30
10
20
30
10
20
30
10
20
30
40
50
60
70
80
Poly
prop
ylen
e
Poly
prop
ylen
e
Poly
imid
e
Poly
styr
ene
Poly
este
r
PVC
FEP Po
lyca
rbon
ate
PVDC
90:10 Water:Ethanol - Based Inks
UV - Based Inks
Ink Types
Figure 7.16 Comparison of polar and nonpolar polymer materials with predominant ink surface energies
The list of flexible polymeric roll materials suitable for atmospheric plasma pro-cessing is expansive. Mainstream resin types include polypropylene (homopoly-mers, heterophasic copolymers, and random copolymers), polyethylene (low, medium, and high density polyethylene resins), a family of specialty polyolefins which includes polybutene-1, advanced polypropylene resins from in-reactor alloy-ing processes and polypropylene compounds, and fluoropolymers. By process type, these materials (in mono- or multiple layers) can be generally represented by the following:
� Film extrusion (blown and cast) � Flexible packaging, such as for food, textiles, consumer products, industrial products, medical products.
� Agricultural � Construction � Materials handling, including stretch wrap and shrink wrap � Electronics � Anti-corrosive linings � Non-stick roll covers � Pharmaceutical cap liners � Automotive airbag systems.